Cytogenotoxic, insecticidal, and phytotoxic activity from biomass extracts of the freshwater algae Nitella furcata.

Agroecology, the application of ecological concepts to agricultural production, has been developing over the last years with consequent promotion for discovery of bioactive compounds to control pests and abolish crop diseases. In this context, algae from Nitella genus are characterized by high potential for bioeconomic applications due to (1) available biomass for harvesting or cultivation and (2) production of allelochemicals, which present a potential to protect field crops from insect infestation. Therefore, this study aimed to determine primary and secondary metabolites derived from aqueous and hydroethanolic extracts of Nitella furcata and to evaluate phytotoxic, cytogenotoxic, insecticidal, and pro-oxidative activities of these extracts. Determination of metabolites showed the presence predominantly of carbohydrates, proteins, phenols, and flavonoids in hydroethanolic extract. Both extracts of N. furcata interfered in the germination of seeds and development of seedlings of Lactuca sativa, with hydroethanolic extract exhibiting greater inhibition. Both extracts also interfered with meristematic cells of Allium cepa as evidenced by chromosomal alterations and higher pro-oxidative activity. Aqueous extract at 5 and 0 mg/ml produced 100% insect mortality. Further, hydroethanolic extract at 0 mg/ml was lethal immediately upon exposure. Therefore, results demonstrate that N. furcata is potential algae species to be considered for development of environmental and ecotoxicological studies as a source of compounds with potential use in agroecological strategies.

Phytotoxic, cytogenotoxic, and insecticidal activities of compounds from extracts of freshwater Lyngbya sp.

The development of agroecology has promoted the discovery of new bioactive compounds that might act as biocides to control infections and microbial contamination. Algae belonging to Lyngbya genus produce several allelochemicals, which are compounds with crop protection potential. The present study aimed to examine primary and secondary compounds derived from Lyngbya sp. extracts (aqueous and hydroethanolic) on phytotoxic, cytogenotoxic, and insecticidal activities. Determination of compounds indicated the presence predominantly of proteins and flavonoids. The extracts presented physicochemical characteristics that produced (1) 89% germination inhibition using hydroethanolic extract and (2) diminished development of seedlings of L. sativa by hydroethanolic extract as evidenced by reduced radicles length in 83.54%. Aqueous and hydroethanolic Lyngbya sp. extracts significantly interfered with meristematic cells of A. cepa, as evidenced by chromosomal alterations and aberrant mitotic phases in cells. Extracts also exhibited pro-oxidative activity and a potent insecticidal potential on S. zeamais, indicating that the hydroethanolic extract produced 100% insect mortality at 75 mg/ml after 48 hr while the aqueous extract initiated 90% mortality at the same concentration after 82 hr. Therefore, data demonstrate that Lyngbya genus provides basic information for new environmental and ecotoxicological studies to seek a possible source of proteins and flavonoids to be used in agroecological management.

Comparison of closure vs non-closure of the peritoneal layer in the formation of postoperative adhesions to the abdominal wall

Este estudo experimental foi realizado em 21 caes submetido quer a sutura manual, quer a sutura mecanica de anastomose colo-colica. Nestes animais foi analizada a formacao de aderencias a parede abdominal nos casos em que a camada peritoneal foi fechada (n=6) e nos casos em que o peritoneo foi fechado com sutura continua de fio poligalactina 910 (n=5), catgut cromado (n=5) e seda (n=5). Tambem procurou-se verificar qual material causou o menor grau de aderencias a linha de sutura. A divisao em grupos foi randominzada quanto a sutura (n=5) e nao sutura do peritoneo (n=6). No grupo em que o peritoneo nao foi fechado, todos os animais foram submetidos a anastomose colo-colica com sutura manual em plano unico com seda 3-0. No grupo em que o peritoneo foi fechado com fio de poligalactina, a anastomose colo-colica tambem foi manual...